Katie can't leave her house during the day: she has a rare disease that makes even the smallest amount of sunlight deadly. But everything changes when one night, singing her heart out on a deserted station platform, she meets Charlie. Before the night is out, Katie is smitten. But she hasn't told Charlie her secret. She just wants to have her normal love story, before reality kicks in. Lost in her night-time summer romance, Katie knows that love will light the way.